Reinforced rigid insulation

ABSTRACT

A reinforced insulation assembly is disclosed. The assembly includes insulation, a reinforcement layer, and an adhesive for attaching the reinforcement layer to a surface of the insulation. The reinforced layer is fully immersed within the adhesive and penetrates the surface of the insulation.

INCORPORATION BY REFERENCE

This application claims the benefit of U.S. Provisional PatentApplication 62/326,506 filed on Apr. 22, 2016, and U.S. Non-Provisionalpatent application Ser. No. 15/493,638, filed on Apr. 21, 2017, whichare both incorporated herein by reference as if fully set forth.

FIELD OF INVENTION

The present invention relates to industrial insulation, and moreparticularly relates to high-temperature industrial insulation.

BACKGROUND

Rigid insulation for high-temperature applications is well known.Insulation is required for energy conservation, personnel protection,condensation control, freeze protection, noise reduction, and fireprotection. Some rigid insulation is very brittle, which can causebreaking, abrasions, crushing, and/or pulverizing during handling of therigid insulations. One known type of rigid insulation includescrystalline bonds between granular particles to provide the rigid shapeof the insulation. These crystalline bonds are extremely brittle andcrack very easily. Other types of known rigid insulation include airfilled solids with air bubbles. While air provides excellent insulationproperties, these air bubbles are susceptible abrasions, pulverization,and crushing.

Perlite silicate is one type of known rigid insulation. Perlite silicatehas high compression strength and insulates a wide temperate range (i.e.125° F. to 1200° F.). Perlite silicate is non-combustible and serves asa corrosion inhibitor. Perlite silicate is relatively delicate due toits granular structure and crystalline bonds which includes air bubbles,making perlite silicate prone to cracking, crumbling, and abrading.During handling, perlite silicate can shift or otherwise rub againstadjacent surfaces causing undesirable dust and particulate. Perlitesilicate is also prone to complete fractures and cracking duringpre-installation transportation and handling.

Due to the delicate properties of rigid insulation, it would bedesirable to provide an improved insulation assembly that resistsbreaking, crushing, abrading, pulverizing, and excessive friability. Oneknown method for improving the durability of insulation is to add loosefibers to the insulation, such as disclosed in U.S. Pat. No. 3,886,076.Adding fibers to insulation has been a standard method for reinforcementof granular, rigid high temperature industrial insulation. Duringmanufacturing, it is difficult to get the loose fibers to homogeneouslymix within the insulation prior to molding or forming. In addition,utilizing loose fibers in the manufacturing process causes additionalwear and tear on the standard manufacturing equipment, in addition toincreased need for maintenance and cleaning of equipment. Adding loosefibers to insulation requires advanced and costly manufacturingtechnologies and processes to ensure adequate distribution of thefibers. Adding loose fibers to insulation is also relatively expensivedue to the cost of the maintaining the manufacturing equipment. In orderto have any effect on flexural strength, it is necessary to introduce alarge volume of the fibers. However, adding a large volume of fibers toknown insulation elements tends to disrupt the insulation properties ofthe insulation element. Finally, extensive testing of various fibers,including the composition, amount, and mode of dispersal, has proventhat that the addition of loose fibers to insulation is ineffective atproviding any significant improvement in flexural strength or reductionof the cracking, breaking, or friability issues that are known to limitthe use of certain rigid high temperature industrial insulations.Further testing showed that the inability of the loose fibers toincrease flexural strength was largely due to the fact that the bondbetween the loose fibers and the crystalline binder in the rigidinsulation was too brittle and weak to increase flexural strength orreduce cracks, breakage, and friability.

It would be desirable to provide reinforcement for rigid insulation thatis flexible and durable, that does not interfere with the structure andperformance of the insulation itself, and also reduces dust.

SUMMARY

An improved reinforced insulation assembly that reduces friability,improves durability, and reduces cracking, breaking and formation ofdust is provided.

In one embodiment, the reinforced insulation assembly includesinsulation, a reinforcement layer, and adhesive for attaching thereinforcement layer to a surface of the insulation.

In one embodiment, the reinforced insulation assembly includes areinforcing agent, a rigid insulation, and a binder that interacts withboth the insulation and the reinforcing agent to transfer properties ofthe reinforcing agent to the rigid insulation.

In another embodiment, the reinforced insulation assembly includesinsulation formed from pre-formed or molded rigid perlite silicate, andthe insulation includes a porous surface. In one embodiment, areinforcement layer is formed from an open weave fiber. Adhesiveattaches the reinforcement layer to the insulation. The reinforcementlayer is embedded within or coated with the adhesive, and the adhesivepenetrates the porous surface of the insulation.

In one embodiment, the adhesive is selected from the group consistingof: polyvinyl alcohol adhesive, acrylic adhesive, vinyl acrylicadhesive, clay alcohol adhesive, starch/dextrin adhesive, vinyl acetateethylene adhesive, and starch clay polyvinyl alcohol adhesive.

In another embodiment, a method of producing a reinforced insulationassembly is provided. The method includes (a) providing a pre-formed ormolded rigid insulation, (b) applying adhesive to a surface of thepre-formed rigid insulation, and (c) pressing a reinforcement layeragainst the surface of the pre-formed rigid insulation including theadhesive to fix the reinforcement layer to the pre-formed rigidinsulation, such that the reinforcement layer is fully immersed orcoated with the adhesive.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing Summary and the following detailed description will bebetter understood when read in conjunction with the appended drawings,which illustrate a preferred embodiment of the invention. In thedrawings:

FIG. 1A is perspective view of a reinforced rigid insulation accordingto a first embodiment.

FIG. 1B is a side cross sectional view of the reinforced rigidinsulation of FIG. 1A.

FIG. 1C is a perspective view of the reinforced rigid insulation ofFIGS. 1A and 1B in a pre-assembled state.

FIG. 2 is a perspective view of a reinforced rigid insulation accordingto a second embodiment.

FIG. 3 is a perspective view of a reinforced rigid insulation accordingto a third embodiment

FIG. 4 is a perspective view of one embodiment of a reinforcement layer.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Certain terminology is used in the following description for convenienceonly and is not limiting. The words “front,” “rear,” “upper” and “lower”designate directions in the drawings to which reference is made. Thewords “inwardly” and “outwardly” refer to directions toward and awayfrom the parts referenced in the drawings. A reference to a list ofitems that are cited as “at least one of a, b, or c” (where a, b, and crepresent the items being listed) means any single one of the items a,b, or c, or combinations thereof. The terminology includes the wordsspecifically noted above, derivatives thereof and words of similarimport.

Referring to FIGS. 1A-1C, a reinforced insulation assembly 10 isdisclosed. The reinforced insulation assembly 10 includes three primarycomponents: insulation 20, a reinforcement layer 30, and adhesive 40. Inan embodiment, the adhesive 40 is applied to an outer surface of theinsulation 20, and the reinforcement layer 30 is bonded to theinsulation 20 via the adhesive 40. In another embodiment, the adhesive40 is applied to an inner surface of the insulation 20 with respect toan underlying component that is to be insulated. Alternatively, theadhesive 40 can be applied to the reinforcement layer 30 and bonded tothe insulation 20. These components are described in more detail below.

In one embodiment, the insulation 20 is an industrial insulation forhigh-temperature applications. As used herein, high-temperatureapplications is understood to mean an application experiencingtemperatures between 601° F. and 1500° F. In one embodiment, theinsulation 20 is granular. Granular is understood to mean a materialcomposed of small nodules with voids, hollow spaces, or gaps. In oneembodiment, the insulation 20 is formed from perlite silicate or calciumsilicate. More preferably, the insulation 20 is formed from perlitesilicate. In one embodiment, perlite silicate has as operatingtemperature limit of at least 1200° F. The perlite silicate preferablyhas a thickness of 1 inch to 4 inches. At 100° F., perlite silicateexhibits the following thermal performance characteristics: 0.47Btu*in/(hr*ft²*° F.) and 0.068 W/m° K. At 200° F., perlite silicateexhibits the following thermal performance characteristics: 0.51Btu*in/(hr*ft²*° F.) and 0.074 W/m° K. At 400° F., perlite silicateexhibits the following thermal performance characteristics: 0.62Btu*in/(hr*ft²*° F.) and 0.089 W/m° K. At 600° F., perlite silicateexhibits the following thermal performance characteristics: 0.74Btu*in/(hr*ft²*° F.) and 0.107 W/m° K.

In one embodiment, the insulation 20 is a pre-formed or molded rigidinsulation layer that is configured to surround a pipe, elbow, tank,valve, or any other component requiring high-temperature insulation. Oneof ordinary skill in the art would recognize from the present disclosurethat the insulation 20 can be formed to have a variety of shapes ordimensions, such as straight pipes, pipe junctures, bent pipes, largegauge pipes, small gauge pipes, etc.

In one embodiment, the reinforcement layer 30 and the adhesive 40 isapplied to a top or bottom surface of the insulation 20. In anotherembodiment, the reinforcement layer 30 and the adhesive 40 can beapplied to side edges of insulation 20.

The reinforcement layer 30 is preferably formed from a fabric, mesh,film, foil, scrim, or other material. In one embodiment, thereinforcement layer is a fine mesh scrim made of fiberglass thread. Inone embodiment, the fiberglass thread has a diameter of 0.1524 mm. Theterm mesh can include any type of layer of material including aplurality of openings or channels. In a preferred embodiment, thereinforcement layer 30 is formed from fiberglass mesh. In otherembodiments, the reinforcement layer 30 is preferably formed from apolymer mesh, such as polyethylene mesh or polypropylene mesh. In apreferred embodiment, the reinforcement layer 30 defines a mesh having agrid profile defined by a plurality of openings, and each openingpreferably defines an interstitial space. The openings preferably have alength of 1 mm to 10 mm and a width of 1 mm to 10 mm. In one embodiment,each one of the plurality of openings has a 3 mm length and a 3 mmwidth. The combination of the size of the openings and the viscosity ofthe adhesive 40 ensures that adhesive 40 seeps through the interstitialspace of the openings of the reinforcement layer 30 and into contactwith the insulation 20. Significantly smaller grid profiles can prohibitadequate seepage of the adhesive 40 through the reinforcement layer 30to the insulation 20, while significantly larger grid profiles canreduce strength characteristics of the reinforcement layer 30. Thereinforcement layer 30 preferably covers between 20% to 100% of at leastone surface 22 of the insulation 20. The reinforcement layer 30 can beapplied a single sheet, as a plurality of strips, or any otherconfiguration. The reinforcement layer 30 more preferably covers 90% ofthe at least one surface 22 of the insulation 20. In one embodiment, thereinforcement layer 30 covers 100% of the at least one surface 22 of theinsulation 20.

The reinforcement layer 30 has a relatively high tensile strengthcompared to the insulation 20. The reinforcement layer 30 strengthensthe insulation 20 when adhered to the insulation to help minimize crackformation and propagation. In one embodiment, the reinforcement layer 30is a bi-directional mesh of fibers. The dual direction of the fibersreinforces the bonds of the insulation. Bidirectional fibers in thereinforcement layer 30 further help prevent crack formation andpropagation in the insulation 20. In one embodiment, multidirectionalfibers are provided, for example a triangular weave, to reinforce thereinforcement layer 30. FIG. 4 shows one embodiment of the reinforcementlayer 30′. As shown in FIG. 4, the reinforcement layer 30′ includes amesh having a grid profile. One of ordinary skill in the art wouldrecognize from the present disclosure that the different types ofreinforcement layers 30 and 30′ can be interchanged. In one embodiment,the reinforcement layer 30 includes fibers having a relatively smalldiameter (i.e. 0.10 mm to 0.20 mm), which improves the bond between thereinforcement layer 30 and the insulation 20. The small diameter of thefiber allows the adhesive 40 to flow around the fibers and bond to theinsulation 20. The density of the reinforcement layer 30 is selected toensure that the reinforcement layer 30 is coarse enough to allowadhesive to flow through the reinforcement layer 30 to the insulation20, but also fine enough to provide sufficient strength for preventingcracks. The reinforcement layer 30 is also thin enough so as to notsignificantly alter the outer diameter of the assembly 10. Thereinforcement layer 30 has a relatively high temperature tolerance thatallows the reinforcement layer 30 to withstand relatively high operatingtemperatures of an underlying insulated component.

In one embodiment, once the reinforced insulation assembly 10 isassembled, the reinforcement layer 30 is fully encased within theadhesive 20, as shown most clearly in FIG. 1B. The adhesive 40 fullysurrounds a top surface and a bottom surface of the reinforcement layer30, as well as fills in any interstitial spaces contained within thereinforcing layer or reinforcing agent. In one embodiment, a depth (d)of the reinforcement layer 30 in the fully formed reinforced insulationassembly 10 (including a top layer of the adhesive 40) is between 1.5 mmto 10 mm. In another embodiment, the adhesive 40 only coats thereinforcement layer 30, i.e. the adhesive 40 contacts only one side ofthe reinforcement layer 30.

The reinforcement layer 30 preferably has a yarn tex (c-glass) warpvalue of 30×2 and a weft value of 45. A weight of the reinforcementlayer 30 is approximately 45 g/m². A density count of the reinforcementlayer 30 per 25 mm has a warp value of 10 and a weft value of 10. Atensile strength of the reinforcement layer 30 is approximately 450 N/(5cm*20 cm) for a warp, and 450 N/(5 cm*20 cm) for a weft. Thereinforcement layer 30 is preferably a leno weave structure. Thereinforcement layer 30 preferably has a resin content of approximately13-15%. The resin in the reinforcement layer 30 is preferably an acrylicresin. In one embodiment, the reinforcement layer 30 has analkali-resistant % of approximately 65% in a warp direction, andapproximately 65% in a weft direction. This percentage is calculated asa percentage of tensile strength after 28 days of immersion in asolution of 5% NaOH.

The adhesive 40 is selected to provide a strong bond to both theinsulation 20 and the reinforcement layer 30. In one embodiment, theadhesive 40 is a low viscosity polyvinyl acetate adhesive. In apreferred embodiment, the adhesive 40 is a vinyl acetate ethylene (VAE)based adhesive. The adhesive 40 has a viscosity that allows the adhesive40 to seep through the grid defined by the reinforcement layer 30 andinto a surface 22 of the insulation 20. The insulation 20 can include aporous surface 22, such as provided by a granular insulation, to promoteseepage of the adhesive 40 into the insulation 20. This leads toeffective wetting of the adhesive 40 with respect to the insulation 20.

Penetration of the adhesive 40 into the insulation 20 improves theflexural strength of the reinforced insulation assembly 10 and reducesvulnerability to cracking, faults, and breakage. The adhesive 40preferably seeps through the interstitial spaces defined by thereinforcement layer 30 and penetrates the surface 22 of the insulation20 to a penetrative depth (d_(p)) of 0.25 mm to 3.0 mm. The penetrativedepth of the adhesive 40 is controlled to ensure the adhesive 40 doesnot penetrate too deep into insulation 20 and adversely affect thestructure of the insulation 20, thus reducing its insulating capability.A total depth (d′) of the combination of the reinforcement layer 30 andthe adhesive 40, including the penetrative depth (d_(p)) is also shownin FIG. 1B. In one embodiment, this total depth (d′) is between 1.0 mmto 13.0 mm.

In one embodiment, the insulation 20 receives a surface treatment priorto applying the adhesive 40 and prior to laying the reinforcement layer30 on the insulation 20. In one embodiment, a surfactant can be appliedto a surface 22 of the insulation 20 to improve penetration of theadhesive 40 into the insulation 20. In one embodiment, the surfactant isAnatrox BL-240 or a general non-ionic surfactant as known in the art. Inanother embodiment, other surface modifications can be applied to theinsulation 20, such as scoring, texturing, bores, etc., to improvepenetration of the adhesive 40 into the insulation 20. The properties ofthe adhesive 40 are selected to ensure that the adhesive 40 fullysaturates and encapsulates the reinforcement layer 30. In addition toimproving the strength of the insulation assembly 10, the adhesive 40provides a protective buffer of the reinforcement layer 30 from theinsulation 20. In one embodiment, the insulation 20 can include a sodiumsilicate based binder, which is corrosive to the reinforcement layer 30.The adhesive 40 provides a barrier to prevent corrosion of thereinforcement layer 30 via contact with the insulation 20. In thisinstance, the adhesive 40 acts as a sealant to protect the reinforcementlayer 30.

The adhesive 40 is selected such that the adhesive 40 is able topenetrate and bond to the surface of the insulation 20. The adhesive 40must be able to penetrate the porous surface of the granular insulation20, thus forming a mechanical adhesion with the insulation 20 that isstronger than the cohesive forces within the insulation 20. This featureensures that if/when the joint fails, the failure occurs within theinsulation 20 (i.e. the adherend). Penetration of the adhesive 40 intothe granular insulation 20 is dependent on the composition of theadhesive 40 in addition to its the viscosity.

While the adhesive 40 must have sufficient strength to bond theinsulation 20 and the reinforcement layer 30, the adhesive 40 must alsobe flexible enough within the service temperature (i.e. ambienttemperature) to withstand forces such as impact, vibration, and otherstresses. The adhesive 40 must also be able to bond dissimilar materialswith different coefficients of thermal expansion, i.e. the insulation 20and the reinforcement layer 30. To do this, the adhesive 40 must have alow glass transition temperature, so that the service temperature isabove the glass transition temperature. When an adhesive is above theglass transition temperature, polymers within the adhesive alter theirstate from a glass-like rigid solid to a more flexible, rubberycompound. An adhesive that works below its glass transition temperature,i.e. CP-97 or a rigid epoxy, may provide stronger bonds but is verybrittle, and may fail when mechanically stressed. Adhesives withpolymers with relatively higher glass transition temperatures canachieve a lower overall glass transition temperature through theaddition of plasticizers. The adhesive 40 is selected to ensure that theadhesive 40 is able to coat and bond to the reinforcement layer 30.Fibers within the insulation 20 (whether singular, dispersed fibers orembedded in a fibrous mesh) typically fail due to the lack of strengthin a bond that does not include the adhesive 40.

In one embodiment, the adhesive 40 is selected from the group consistingof: polyvinyl alcohol, acrylic, vinyl acrylic, clay alcohol,starch/dextrin, vinyl acetate ethylene, and starch clay polyvinylalcohol based adhesives. In one embodiment, the adhesive 40 is awater-based glue. In another embodiment, the adhesive 40 is asolvent-based glue. In one embodiment, the melting temperature of theadhesive 40 is at least 250° F. Melting temperature is defined as thetemperature at which constituents of the adhesive undergo irreversiblephysical degradation. A relatively high blocking temperature for theadhesive 40 is selected to ensure that the adhesive 40 does not ooze,seep, or melt, particularly during storage, transportation, orpre-installation. The blocking temperature of the adhesive 40 ispreferably at least 115° F. The term blocking temperature is understoodto refer to the temperature at which undesired adhesion between touchinglayers of material occurs under moderate pressure during storage or use(ASTM D 907-06). The viscosity of the adhesive 40 is preferably between1,000 cP and 10,000 cP. This viscosity value ensures that the adhesive40 penetrates the insulation 20 and reinforcement layer 30, while alsohaving a sufficient viscosity to provide tackiness such that theadhesive 40 is easy to handle prior to assembly. The adhesive 40 mustalso provide sufficient tackiness to hold the reinforcement layer 30 inplace prior to drying. The adhesive 40 preferably has a glass transitiontemperature that is greater than −4° F. and less than 86° F. Theadhesive 40 preferably has a pH value between 4 and 7. This pH value isselected to prevent corrosion of the pipe surrounded by the reinforcedinsulation assembly 10, as well as any underlying insulation, and/ormetal jacketing surrounding the insulation.

In one embodiment, the adhesive 40 is a polyvinyl alcohol basedadhesive. In this embodiment, the adhesive 40 improves a flexuralstrength of the overall reinforced insulation assembly 10 byapproximately 250% compared to non-treated insulation. Non-treatedinsulation, as used herein, is defined as insulation that does notinclude adhesive or a reinforcement layer. The flexural strength wastested according to ASTM test method C203. ASTM testing method C203includes placing a test specimen on two support bars and loading thetest specimen at a midway point between the two support bars until thetest specimen ruptures. The ASTM C203 testing method provides asurrogate for determining the resistance of an insulation to cracks andbreakage. The flexural strength provides sufficient strength andprevents cracks, faults, and breaking. In the polyvinyl alcohol basedadhesive embodiment, the viscosity of the adhesive 40 is approximately4,000 cP. The solid content of this adhesive 40 is approximately 12% to14%. The density of this adhesive 40 is approximately 834. The glasstransition temperature of this adhesive 40 is approximately 86° F.

In one embodiment, the adhesive 40 is an acrylic based adhesive. In thisembodiment, the adhesive 40 improves a flexural strength of the overallreinforced insulation assembly 10 by approximately 415% compared tonon-treated insulation. In this embodiment, the viscosity of theadhesive 40 is approximately 1,800 cP. The solid content of thisadhesive 40 is approximately 54%. The density of this adhesive 40 isapproximately 9. The glass transition temperature of this adhesive 40 isapproximately 23° F.

In one embodiment, the adhesive 40 is a vinyl acrylic based adhesive. Inthis embodiment, the adhesive 40 improves a flexural strength of theoverall reinforced insulation assembly 10 by approximately 700% comparedto non-treated insulation. In this embodiment, the viscosity of theadhesive 40 is approximately 4,000 cP. The solid content of thisadhesive 40 is approximately 53.5%. The density of this adhesive 40 isapproximately 8.9. The glass transition temperature of this adhesive 40is approximately 5° F.

In one embodiment, the adhesive 40 is a clay alcohol based adhesive. Inthis embodiment, the adhesive 40 improves a flexural strength of theoverall reinforced insulation assembly 10 by approximately 158% comparedto non-treated insulation. In this embodiment, the viscosity of theadhesive 40 is between 2,800 cP and 3,300 cP. The solid content of thisadhesive 40 is between 19% and 23%. The density of this adhesive 40 isbetween 8.9 and 9.9. The glass transition temperature of this adhesive40 is approximately 86° F.

In one embodiment, the adhesive 40 is a starch/dextrin based adhesive.In this embodiment, the adhesive 40 improves a flexural strength of theoverall reinforced insulation assembly 10 by approximately 141% comparedto non-treated insulation. In this embodiment, the viscosity of theadhesive 40 is approximately 2,000 cP. The solid content of thisadhesive 40 is approximately 58%. The density of this adhesive 40 isapproximately 9. The glass transition temperature of this adhesive 40 isapproximately 93° F.

In one embodiment, the adhesive 40 is a vinyl acetate ethylene basedadhesive. In this embodiment, the adhesive 40 improves a flexuralstrength of the overall reinforced insulation assembly 10 byapproximately 284% compared to non-treated insulation. In thisembodiment, the viscosity of the adhesive 40 is approximately 1,500 cP.The solid content of this adhesive 40 is approximately 54.3%. Thedensity of this adhesive 40 is approximately 9. The glass transitiontemperature of this adhesive 40 is approximately 14° F.

In one embodiment, the adhesive 40 is a starch clay polyvinyl alcoholbased adhesive. In this embodiment, the adhesive 40 improves a flexuralstrength of the overall reinforced insulation assembly 10 byapproximately 192% compared to non-treated insulation. In thisembodiment, the viscosity of the adhesive 40 is approximately 1,100 cP.The solid content of this adhesive 40 is approximately 53.5%. Thedensity of this adhesive 40 is approximately 8.6 The glass transitiontemperature of this adhesive 40 is approximately 50° F.

The embodiment of FIGS. 1A-1C includes rectangular insulation 20. Theembodiments of FIGS. 2 and 3 are identical to the embodiment of FIGS.1A-1C except the shape of the insulation 20 is modified. In FIG. 2, theinsulation 120 has a curved profile. The remaining components, i.e. theassembly 110, reinforcement layer 130, and adhesive 140, are identicalto the first embodiment. The curved insulation 120 is configured toaccommodate a pipe or other cylindrical structure. In FIG. 3, theinsulation 220 has a segmented torus profile, which is configured toaccommodate a pipe juncture. The remaining components, i.e. the assembly210, reinforcement layer 230, and adhesive 240, are identical to thefirst embodiment. One of ordinary skill in the art would recognize fromthe present disclosure that the assemblies and methods described hereincan be modified such that the insulation can accommodate any variety ofsizes or shapes.

The reinforcement system is applied to a radially outer surface 22 ofthe insulation 20. This ensures that the reinforcement layer 30 andadhesive 40 do not interfere with the heat transfer and insulationprovided between the insulation 20 and the insulated pipe, which arearranged directly facing each other.

In another embodiment, a method of producing a reinforced insulationassembly 10 is provided. The method includes (a) providing a pre-formedor molded rigid insulation 20, (b) applying an adhesive 40 to a surface22 of the pre-formed rigid insulation 20, and (c) pressing areinforcement layer 30 against the surface 22 of the pre-formed rigidinsulation 20 including the adhesive 40 such that the reinforcementlayer 30 is fully covered or immersed within the adhesive 40. In oneembodiment, the adhesive 40 is heated to a temperature of 120° F. to180° F. prior to step (b). In one embodiment, the adhesive 40 is heatedto 150° F. After step (c), the adhesive 40 is cured. In one embodiment,the adhesive 40 is cured via heating. During heated curing, the adhesive40 is preferably heated to a temperature of 250° F. to 350° F. for threeto ten minutes. In one embodiment, the heated curing is performed forfive minutes.

In one embodiment, the adhesive 40 is only applied to the insulation 20during step (b). In another embodiment, the adhesive 40 is applied toboth the insulation 20 and the reinforcement layer 30 in step (b). Inone embodiment, the reinforcement layer 30 is placed onto the insulation20 first, and then adhesive 40 is applied to the combination of thereinforcement layer 30 and the insulation 20 such that the adhesive 40seeps through the reinforcement layer 30 into contact with theinsulation 20. In another embodiment, the adhesive 40 is applied to theinsulation 20 separately, and applied to the reinforcement layer 30separately, after which the adhesive-coated insulation 20 andadhesive-coated reinforcement layer 30 are pressed together for bonding.The reinforcement layer 30 is cut to accommodate a shape of theinsulation 20 or a shape of a critical area that must be reinforced.Strips or other shapes of reinforcement layers 30 can be provided forirregularly shaped applications. Cutting of the reinforcement layer 30can be performed prior to step (c) or after step (c).

In one embodiment, the insulation 20 is fully formed or molded and in ahardened state after step (a) and prior to steps (b) and (c). Thisensures that the mesh of the reinforcement layer 30 in the fully formedinsulation assembly 10 is arranged on an outer surface 22 of theinsulation 20, and not within or inside the insulation 20. Thereinforcement layer 30 and the adhesive 40 both contribute to preventfriability, abrasions, dust, and other issues with non-reinforcedinsulation. The combination of the reinforcement layer 30 and theadhesive 40 both improve the strength of the insulation assembly 10 aswell as provide a protective outer layer for a surface 22 of theinsulation 20, thus reducing friability. The adhesive 40 individuallyhelps to prevent abrasions and formation of dust. In certainapplications, adhesive 40 can be applied to an entire outer surface ofthe insulation 20, while the reinforcing layer 30 is only applied incertain critical portions of the insulation 20.

The present reinforced insulation assembly does not affect performanceof the insulation with respect other critical ASTM specifications. Forexample, the reinforced insulation assembly does not detrimentallyaffect performance of the insulation with respect to ASTM C1045 forthermal conductivity, ASTM C795 for 28-day corrosion, as tested by ASTMC692 and ASTM C871, or accelerated corrosion by ASTM C1671 and ASTMC871.

Embodiments of the insulation, adhesive, and reinforcement layer used inthe method are identical to the embodiments of the insulation, adhesive,and reinforcement layer described above.

What is claimed is:
 1. A method of producing a reinforced insulation assembly, the method comprising: (a) providing a high-temperature rigid insulation that is pre-formed or molded; (b) applying an adhesive to a reinforcement layer defining a mesh such that the reinforcement layer is fully immersed in the adhesive; and (c) pressing the reinforcement layer against the outer surface of the high-temperature rigid insulation including the adhesive, such that the adhesive penetrates the outer surface of the high-temperature rigid insulation.
 2. The method according to claim 1, wherein the high-temperature rigid insulation is hardened after step (a) and prior to step (c).
 3. The method according to claim 1, wherein the adhesive seeps through the mesh defined by the reinforcement layer and penetrates the outer surface of the high-temperature rigid insulation to a depth of 0.25 mm to 3.0 mm.
 4. The method according to claim 1, further comprising curing the adhesive after step (c) by heating.
 5. The method according to claim 1, further comprising applying the adhesive separately to the outer surface of the high-temperature rigid insulation.
 6. The method according to claim 1, wherein the high-temperature rigid insulation is formed from perlite silicate or calcium silicate.
 7. The method according to claim 1, wherein the adhesive has a melting temperature greater than 250° F., a blocking temperature greater than 115° F., a glass transition temperature greater than −4° F. and less than 86° F., a viscosity between 1,000 cP and 10,000 cP, and a pH between 4 and
 7. 8. The method according to claim 1, wherein the reinforcement layer is a fiberglass or polymer mesh.
 9. The method according to claim 1, wherein step (b) includes applying the adhesive to a single outer surface of the high-temperature rigid insulation.
 10. The method according to claim 1, wherein the adhesive is selected from the group consisting of: polyvinyl alcohol adhesive, acrylic adhesive, vinyl acrylic adhesive, clay alcohol adhesive, starch/dextrin adhesive, vinyl acetate ethylene adhesive, and starch clay polyvinyl alcohol adhesive.
 11. The method according to claim 1, wherein a combination of the adhesive and the reinforcement layer have a depth of 1.0 mm to 13.0 mm.
 12. The method according to claim 1, wherein the high-temperature rigid insulation is capable of an operating temperature between 601° F.-1500° F.
 13. The method according to claim 1, wherein the reinforced insulation assembly formed according to steps (a)-(c) includes at least four layers, including: a first layer formed of the high-temperature rigid insulation, a second layer directly above the first layer including a mixture of the adhesive and the high-temperature rigid insulation, a third layer directly above the second layer including the adhesive, and a fourth layer directly above the third layer including a combination of the adhesive and the reinforcement layer.
 14. The method according to claim 13, wherein the reinforced insulation assembly includes a fifth layer directly above the fourth layer including the adhesive.
 15. The method according to claim 1, wherein the reinforced insulation assembly formed according to steps (a)-(c) meets ASTM standards tested under ASTM C203.
 16. The method according to claim 1, wherein the adhesive is heated to a temperature of 120° F. to 180° F. prior to step (b).
 17. The method according to claim 16, wherein the adhesive is cured via heating after step (c).
 18. The method according to claim 17, wherein the adhesive is cured via heating to a temperature of 250° F. to 350° F.
 19. The method according to claim 1, wherein the adhesive is heated to a temperature of 120° F. to 180° F. prior to step (b), and the adhesive is cured after step (c) via heating to a temperature of 250° F. to 350° F.
 20. The method according to claim 1, further comprising wrapping the reinforced insulation assembly around a pipe, a tank, or a valve, wherein the adhesive and the reinforcement layer are positioned outwardly relative to the pipe, the tank, or the valve. 